Present invention relates to devices and methods for the treatment and/or diagnosis of anorectal disorders, and more particularly to device and method of treating and/or diagnosing of anorectal disorders by using a medical instrument which is inserted into the anal canal by an applicator.
The anal sphincter includes internal and external portions. The internal anal sphincter is a ring of smooth muscle which surrounds the lower extremity of the rectum and is formed by an aggregation of the involuntary smooth muscle fibers. The internal anal sphincter is under a state of chronic contraction, due both to intrinsic myogenic properties and external innervation. The external anal sphincter is a thin flat plane of striated muscle fibers, under voluntary control, adherent to the integument surrounding the margin of the anus.
Anorectal disorders include anal sphincter spasm, anal fissures, abscesses, fistulae, ulcers, irritation and itching (pruritus ani), hemorrhoids, incontinence, constipation, inflammation, infection, and cancer. Anal sphincter spasm is a condition in which the muscles of the internal anal sphincter are under abnormal tension. This may be caused, for example, by local inflammation. The strong contractions of the internal anal sphincter associated with sphincter spasm often give rise to mucosal ischaemia, resulting in anal fissures, which are painful linear ulcers or crack-like tears in the distal anal canal, which, in the short-term, usually involves only the epithelium and, in the long-term, involves the full thickness of the anal mucosa. Because of the pain of a fissure, the internal anal sphincter may go into spasm, raising pressure within the anus.
Anorectal disorders which involve ulcer or crack in the folds of the anal margin, for example anal fissures, may not be promptly heal because of the high internal anal sphincter spasm and reduction in vascular perfusion at the site. Acute anal fissures which do not heal over time become chronic anal fissures or anal ulcers. Current treatments of chronic anal fissures are directed at relieving sphincter spasm and include dilatation (under anesthesia), or cutting the sphincter (lateral internal sphincterotomy) to reduce the hypertonicity of the internal anal sphincter muscle.
Some devices have been developed for treating anorectal disorders, for example Int. Patent Application No. PCTIIL2006/001446, filed on Dec. 14, 2006, describes a rectally insertable device for localized drug delivery to the anal sphincter of a subject. The device comprises a shell for containing an active pharmaceutical ingredient, the shell being substantially impermeable to the active pharmaceutical ingredient wherein a lower portion of the shell is configured to release the active pharmaceutical ingredient from the shell and wherein when the device is inserted into the rectum of the subject, the lower portion of the shell is proximal to the anal sphincter, such that the active pharmaceutical ingredient is released proximal to the anal sphincter.
Another example is described in International Patent Publication Number WO 2007/094004, which describes a device for prolonged delivery of an active agent to a body cavity. The device is insertable into the cavity of a subject in need. The device includes a non-absorbable, flexible tube of an elongated shape, a removable core element situation within the tube, and a retention mechanism for maintaining the device within the cavity.